This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A067825 #32 Apr 23 2024 08:19:18 %S A067825 2,62,74,134,146,194,254,314,398,404,458,482,494,524,554,566,614,626, %T A067825 662,674,692,734,758,764,794,818,854,914,944,974,998,1034,1094,1124, %U A067825 1154,1214,1238,1286,1322,1394,1454,1514,1538,1574,1646,1658,1682,1754 %N A067825 Even values of k such that sigma(k + 1) > sigma(k). %C A067825 Most terms are == 2 (mod 6), first term == 4 (mod 6) is a(365) = 13474. - _Zak Seidov_, Apr 18 2013 %C A067825 First term == 0 (mod 6) may be 296527606374. - _Jianing Song_, Apr 01 2018 %H A067825 Amiram Eldar, <a href="/A067825/b067825.txt">Table of n, a(n) for n = 1..10000</a> (terms 1..2000 from Zak Seidov) %t A067825 Select[Range[2, 2000, 2], DivisorSigma[1, #] < DivisorSigma[1, # + 1] &] (* _Zak Seidov_, Apr 18 2013 *) %o A067825 (GAP) Filtered([2,4..2000],n->Sigma(n+1)>Sigma(n)); # _Muniru A Asiru_, Apr 03 2018 %o A067825 (PARI) is(n) = !(n%2) && sigma(n + 1) > sigma(n); \\ _Amiram Eldar_, Apr 23 2024 %Y A067825 Cf. A000203 (sigma), A053224. %K A067825 nonn %O A067825 1,1 %A A067825 _Benoit Cloitre_, Feb 08 2002